Development of Hot-rolled High Strength TRIP Steel with Tensile Strength of 780MPa Grade

摘要

High strength steels are used for automotive components to improve safety and fuel efficiency by reducing vehicle weight. These have been developed for various needs because of their ability to adjust properties by modifying the morphology (size, shape, distribution) and volume fraction of individual phases; ferrite (polygonal ferrite, quasi-polygonal ferrite, acicular ferrite), pearlite, bainite and martensite and so forth. In order to meet the demanded properties of high strength steel, dual phase steel have been developed, characterized by a properties showing a low yield strength (low YR), high work hardening rate and large uniform elongation, resulted from a microstructure consisting of a dispersion of a hard phase, martensite, in a soft matrix of ferrite [1].